There are lots of good options, but overall given what you've stated I would highly recommend Ushigoro Nishiazabu (and specifically that one of their multiple locations). On top of the normal courses which are great, for the options I recommend going with the curry (you can get solid korean noodles anywhere, so go for the curry). And for dessert, the sweet potato is a perfect way to end.

The 1man course is a LOT of food; I recommend the 8000yen or if people aren't sure you can do the 6000yen and always do some a la carte addons depending on what people end up really liking.